Q When the dust of conflict concerning Newton's an- LITTLE 

 nouncement of the qualities of light had somewhat JOURNEYS 

 subsided, he turned to his former discovery, the Law 

 of Gravitation, and bent his mighty mind upon it. The 

 influence of the moon upon the Earth, the tilt of the 

 Earth, the flattening at the poles, the recurring tides, 

 the size, weight and distance of the planets now occu- 

 pied Newton's attention. And to properly study these 

 phenomena he had to construct special and peculiar 

 apparatus ^ 



In 1687 the results of his discoveries were brought to- 

 gether in one great book, the " Principia." Newton was 

 then forty-five years old. He was still the Cambridge 

 professor, but was well known in political circles in 

 London on account of having been sent there at vari- 

 ous times to represent the University in a legal way. 

 QHis diplomatic success led to his being elected a 

 member of Parliament. Among other great men whom 

 he met in London was Samuel Pepys who kept a diary 

 and therein recorded various important nothings about 

 " Mr. Isaac Newtown of Cambridge a school-teacher 

 of degree, with a great dignity of manner and pleasing 

 Countenance." It seems Newton thought so well of 

 Pepys that he wrote him several letters, from which 

 Samuel gives us quotations. Pepys really claimed the 

 honor of introducing Newton into good society. 

 Among others with whom Newton made friends in 

 Parliament was Mr. Montague, who shortly after be- 

 came Secretary of the Exchequer. Montague made his 

 friend Newton a Warden of the Mint, with pay about 



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